Yes, for gcc2 we are still using an old Mesa version which has only one rasterizer.

And for gcc4, both renderer are still supported, often you have to try both as they will work or crash in different places, so even there we aren't fully ready to switch to using only the new softpipe.

Thanks.
I guess somewhere a sub object is not allocated due to initial width and height being zeros but when it's resized _mesa_resize_framebuffer try to deference renderbuffer which were never allocated in the first place.